Matamoras, Mexico Discharge

My ancestor W.G. Vaughn was discharged in Matamoras, MX due to surgeons report of dis-ability on 1 Oct, 1846. He served in the 1st MS Inf, Co "F" of the MS rifles. His commanding officer was Col Jefferson Davis. The service record does not state the nature of the dis-ability. Do any other posters have any knowledge of battles around Matamoras around that time period?